Recently, a display and a lighting device using an organic electroluminescence device (organic EL device) have been actively studied for their practical realization. In particular, reducing the cost and sizing up of a display is given as a big issue to be solved. Under such circumstances, the (solution) coating type organic EL device has come to attract more expectations than ever as compared with traditional vacuum deposition type organic EL devices. It is expected that a coating type organic EL device has a high material-use efficiency, is easy in formation of a large-sized display, and is inexpensive regarding the apparatus cost due to elimination of a vacuum system.
Here, the organic EL material for a coating type organic device is divided into the low molecular-based one and the high molecular-based one. In respect of solubility, uniform coating and capability of being formed into a stacked device, a high molecular-based one is preferable. In particular, the development of high molecular-based materials for a hole transporting (injecting) layer which can be used both in a display and a lighting device has been desired.
As for the high molecular-based material for a hole transporting (injecting) layer, one disclosed in Patent documents 1 to 3 can be given. However, these materials provide insufficient hole transporting function (mobility) or insufficient solubility in a coating solvent.
In addition, coating type materials for a hole transporting (injecting) layer are disclosed in Patent documents 4 and 5, in which a polymerizable monomer which is substituted by a vinyl group or the like is applied to a triarylamine-based hole-transporting material, followed by a treatment such as heating to obtain a polymer, whereby a material for a hole transporting (injecting) layer which is insoluble in a solvent of an emitting layer is disclosed (Patent Documents 4 and 5). However, an organic EL device having a hole transporting (injecting) layer obtained from the above-mentioned polymerizable monomer cannot provide sufficient device properties such as a prolonged life (half life) and a high luminous efficiency.